Process for the production of white lead



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R. GREGORY.

PROCESS FOR THE PRODUCTION 0F WHITE LEAD. y APPLlcAnoN FILED APR.18.1921.

RASSRW., Patented Nov., M1922.

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ff'fererx Patented Nov., Ml, i922.

Anagni oratore,

HERBERT GREGORY, oFcONcORn, CALIFORNIA, AssIeNoa To NATIONAL LEAD COMPANY or CALIFORNIA, A CORPORATION OF CALIFORNIA.

PROCESS FOR THE PRODUCTION OF WHITE LEll Application le April 18, 1921. Serial No. 462,222.

To all whom t mary Concern.' v

Be it known that I, HERBERT GREGORY, a

citizen of the United States, residing at Concord, in the county of Contra Costa, State e of California, have invented a new and useful Process forthe Production of White Lead, of which the following is a specification in such full and clear terms as will enable those skilled in the art to construct andv use the same. l

This invention relates to a process for the production of white lead and its object is to simplify the oxidation of the lead while preserving the beneficial result attained by the l5 old style method of treatment.

It will be understood by those skilled in the art that in the production of white lead it is common to surround a series of pots containing the lead and the reagents necessary with material such as wet straw, tan bark or other decomposing materials which will produce sufiicient carbon dioxide to`complete the process and to allow the treatment to continue for a period of from three to four months at the end of which time it will be found that a large per cent of the metallic lead has changed into white lead substan tially of the formula 2PbCO3Pb(0I-I)2.

The disadvantage of the foregoin procedure is that unless great care is ta en to prevent particles of the material used to produce the C02 and to heat the stack,'from getting into the pots white lead will be found to be specked with the material used to cover the pots and in addition where the stacks are made with-a thick layer of tan bark or other decomposing material between each layer of pots that much unnecessary space is wasted. With the present invention artificial heat and moisture are supplied to assist in raising the temperature to the desired point and this heat and moisture may be supplied as long as is deemed necessary to maintain the stack at any given temperature. The control of the temperature and the control ofevaporation Of the reagents used is effected by a suitable flue extending through the stack.

Other objects of the invention will appear as the description proceeds.

An embodiment of the invention is shown in the accompanying drawings in which the samereference numeral is applied to the same portion, throughout but I am aware that there may be modifications thereof.

Fig. l is a perspective view of a series of stacks used to carry out this process.

Fig. 2 is a vertical sectional view of one of y the stacks.

Fig. 3 is a stacks. l y

A stack'housei' consists of a plurality of square chambers supported by posts l to 4 inclusive in such'numbers as the number of stacks requires there being one complete series of posts at the ends of the stack house and at the junction of each chamber with each other chamber.

The stack house is provided with rafters 5 for the support of the roof and the ventilating house 6 and there are overhead tracks 7 and 8 for handling the material to be placed in the several stacks.

Inside the outer walls 9 and l0 of the stack house there are 8posts ll to 18 inclusive which posts support a plurality of louvers 19, said louvers are so inclined that the deplan view of portions of the composing material placed between the louvers and the outer walls 9 and 10 of the stack house as to prevent said materials from fallin inside the stack.' 8e Ihe metallic lead in buckles or other finely divided form is placed within a plurality of n suitable containers 20, said pots or containers being placed inside the stack house and upon each layer of pots there are placed a plurale ity of boards 2l for the support of the next upper layer of pots. At the top there is placed a tight layer of boards 22 which prevents any material from passing through into the inside of the stack. The louvers are placed within the stack house about two feet siX inches distant from the outer walls thereof and the space between the outer walls of the stack and the louvers is completely filled with the tan bark or other material used. When the stack has been filled with lthe pots l they are covered with the boards and a layer of about two feet of tan bark, straw or other decomposing material.

lAdjacent each of the inner posts 11 to 18 of each stack are a plurality of perforated steam pipes 25 and 26 all of said pipes being connected by means of the pipes 28 to 32 inclusive to a main steam supply pipe 33. In order to ventilate the interior of the stack a flue 40 is placed in the center. This Hue has holes in its sides and is open at the top. A cover 41 is placed on the top of the flue by a stairway 37.'

lio

The operation of the process is as follows: Assuming the stack to be ready for charg ing, the space between the louvers of the inner stack and the outer lwalls is filled with' tan bark, straw or other decom osing material. Thereupon the layers `o containers or (pots, in which containers the lead buckles an reagents are placed, are then laced within the inner stack in layers. oards are laid upon each layer o f pots to distribute the weight of the next layer of pots more evenly, and the stack is completely illed. Thereupon a tight cover is put across the toplayer of pots and the stack is then completely covered with -a layer of about two feet thick of the material used to fill the stack at the sides.V Thereupon the mass is heated by the live steam escaping from the several pipes adjacent the inside posts and the stack is heated to such a temperature as hasbeen ascertained by previous experience will v'produce the quickest corrosion of the lead and this temperature will be maintained as long as is deemed necessary to accomplish the desired results. Ordinarily it will be found that white lead may be produced by the process herein described in from 30 to 60 days less than the time required by the old process where e-ach individual pot is covered over with tan bark or straw, and in addition to the above there isv no'danger ofV small particles of tan bark getting into the several pots since the upper layer of material vcan be completely cleaned off before any of the pots-are opened. It

i will also be seen that there is no danger of the pots being broken or disturbed by the sinking of the mass of material upon which they are piled, and the economy of space is greatly increased.

What I claimis as follows, but modifica- The several stacks tainers with -a layer 4of decomposing materials for the purpose of producing carbon dioxide, heating the mass of said materials with steam tothe temperature of most effective chemical action and maintaining such temperature until the lead has been corroded.

2. Aprocess of producing white lead which consists in placing a plurality of receptacles containing-lead in a suitable form for corrosion together with the necessary reagents ina suitable enclosure, covering said enclosure and the mass of receptacles with a complete layer of decomposing materials for the purpose of producing heat and carbon dioxide, heating the mass with steam to the temperature of most effect-ive chemical action and maintaining such temperature together with the necessary moisture until the lead has been suiciently corroded.

3. A process. ofproducing white lead which consists in placing a plurality of layers of receptacles containing/lead in a suitable form for corrosion with the desired reagents in an enclosure, covering the mass of receptacles with a single layer of decom- HERBERT GREGORY. 

